Questions And Answers

I am trying to determine if a piece of equipment can be damaged by a static discharge. I hope that you can provide some information on my questions. The scenario is a battery operated electronic device that transmits a RF signal to a nearby repeater. The device contains ESD sensitive components. All electronic circuit cards along with the batteries are completely enclosed in a metal cabinet. The metal cabinet is located within a water and air tight plastic case and is buried just inches below the surface with only the antenna exposed. The questions regarding this scenario are: How susceptible is this device to damage by a static discharge while in operation? Can a breeze of air cause enough static on the antenna to damage any of the components with in the device? - Eric, Yuma, AZ

Answer

First, the device may be susceptible to ESD or EOS only from the input of the antenna, depending what fields or activity occurs nearby and on the design of the input amplifier. Second, air cannot really charge the antenna enough…….gases do not tribocharge, but the impurities in them (if significant enough, heavy enough and dense enough) can lead to some tribocharging…..you would need a lot of impurities (dust storm), a strong breeze and large surface (of the antenna) to even perceive any charging. The biggest concern may be lightning strikes, depending on the relative positioning of the antenna to other nearby